function to remove duplicate elements from the array code example

Example 1: how to remove duplicates in array in javascript

const numbers = [1 , 21, 21, 34 ,12 ,34 ,12];
const removeRepeatNumbers = array => [... new Set(array)]
removeRepeatNumbers(numbers) // [ 1, 21, 34, 12 ]

Example 2: remove duplicates from array

let chars = ['A', 'B', 'A', 'C', 'B'];
let uniqueChars = [...new Set(chars)];

console.log(uniqueChars);

output:
[ 'A', 'B', 'C' ]

Example 3: remove duplicate value from array

let chars = ['A', 'B', 'A', 'C', 'B'];
let uniqueChars = [...new Set(chars)];

console.log(uniqueChars);

Example 4: remove duplicates in array

uniq = [...new Set(array)];

or 

uniqueArray = a.filter(function(item, pos) {
    return a.indexOf(item) == pos;
})